Home use of a functional electrical stimulation system for standing and mobility in adolescents with spinal cord injury

OBJECTIVE: Functional electrical stimulation (FES) is a technology that may allow some patients with spinal cord injury (SCI) to integrate standing and upright mobility with wheelchair mobility. The purpose of this study was to document the patterns of home and community use of a FES system for standing and mobility. DESIGN: A telephone questionnaire was administered every 1 to 4 weeks for a minimum of 1 year. An interview was given at the end of the study to probe the motivators and barriers to home use. SETTING: Training for use of the FES system was performed in an inpatient pediatric rehabilitation setting. Data collection began after the subjects were discharged to home. PARTICIPANTS: Five adolescents with complete, thoracic-level SCI. INTERVENTION: Subjects participated in a program of FES exercise followed by training in basic mobility skills such as standing transfers, maneuvering, level ambulation, one-handed and reaching activities, and stair ascent/descent. MAIN OUTCOME MEASURE: The frequency with which the FES system was used at home and the activities for which it was utilized were documented. Motivators and barriers to FES home use were examined. RESULTS: Subjects donned the FES system on the average once every 3 to 4 days. Between 51% and 84% of the times donned, the system was used for exercise. The remaining times it was used for standing activities, most commonly reaching, one-handed tasks, and standing for exercise. "Motivators" included being able to do things that would otherwise be difficult, perceiving a healthful benefit or a sense of well-being from standing and exercise, and feeling an obligation to stand as a participant in a research study. "Barriers" to FES use included not finding time to use the system, having difficulty seeing opportunities to stand, and being reluctant to wear the FES system all day.     

33.7 MHz heavy-ion radio frequency quadrupole linac at VECC Kolkata

A 33.7 MHz heavy-ion radio frequency quadrupole (RFQ) linear accelerator has been designed, built, and tested. It is a four-rod-type RFQ designed for acceleration of 1.38 keVu, qA> or =116 ions to about 29 keVu. Transmission efficiencies of about 85% and 80% have been measured for the unanalyzed and analyzed beams, respectively, of oxygen ((16)O(2+), (16)O(3+), (16)O(4+)), nitrogen ((14)N(3+), (14)N(4+)), and argon ((40)Ar(4+)). The system design and measurements along with results of beam acceleration test will be presented.     

On coherence, random-self-reducibility, and self-correction

We study three types of self‐reducibility that are motivated by the theory of program verification. A set A is random‐self‐reducible if one can determine whether an input x is in A by making random queries to an A‐oracle. The distribution of each query may depend only on the length of x. A set B is self‐correctable over a distribution if one can convert a program that is correct on most of the probability mass of to a probabilistic program that is correct everywhere. A set C is coherent if one can determine whether an input x is in C by asking questions to an oracle for C–{x}.?We first show that adaptive coherence is more powerful than nonadaptive coherence, even if the nonadaptive querier is nonuniform. Blum et al.(1993) showed that every random‐self‐reducible function is self‐correctable. It is unknown, however, whether self‐correctability implies random‐self‐reducibility. We show, assuming a reasonable complexity‐theoretic hypothesis, that certain hard, sparse, tally sets exist, and that there is a self‐correctable function which is not random‐self‐reducible. For easily samplable distributions, however, we show that constructing a self‐correctable function that is not random‐self‐reducible is as hard as proving that P is different from PP. Received: 14 June, 1996     

Global modeling of hydrogen using GFDL-AM4.1: Sensitivity of soil removal and radiative forcing

Hydrogen (H₂) has been proposed as an alternative energy carrier to reduce the carbon footprint and associated radiative forcing of the current energy system. Here, we describe the representation of H₂ in the GFDL-AM4.1 model including updated emission inventories and improved representation of H₂ soil removal, the dominant sink of H₂. The model best captures the overall distribution of surface H₂, including regional contrasts between climate zones, when v_d(H₂) is modulated by soil moisture, temperature, and soil carbon content. We estimate that the soil removal of H₂ increases with warming (2–4% per K), with large uncertainties stemming from different regional response of soil moisture and soil carbon. We estimate that H₂ causes an indirect radiative forcing of 0.84 mW m^?2/(Tg(H₂)yr^?1) or 0.13 mW m^?2 ppbv^?1, primarily due to increasing CH₄ lifetime and stratospheric water vapor production.     

Electrodeposition and Corrosion Properties of Zn-V2O5 Composite Coatings

Composite coatings were obtained by electrochemical codeposition of V₂O₅ nanoparticles with zinc, from an additive free acid sulfate bath. The corrosion behavior of electrodeposited Zn and Zn-V₂O₅ composite coatings was investigated in 3.5% NaCl solution using polarization and electrochemical impedance spectroscopy (EIS). The decrease in I _corr values and an increase in R _ct values show the higher corrosion resistant nature of Zn-V₂O₅ coatings. The observed textural modifications of composite coatings are associated with the specific structural modification of Zn crystallites provoked by the adsorption-desorption phenomena occurring on the metal surface, induced by the presence of V₂O₅ nanoparticles. It has been observed that the presence of V₂O₅ nanoparticles favors the [1 0 2] and [1 1 2] texture of zinc matrix. Moreover, the codeposition of V₂O₅ nanoparticles with zinc was found to be favored at pH 3.5 and applied current density 4?A?dm^?2. A considerable grain refinement of the deposit occurred due to incorporation of V₂O₅ nanoparticles and hence improved the preferred orientation of the zinc crystallites.     

Physico‐mechanical properties of nano‐polystyrene‐decorated graphene oxide–epoxy composites

Nano‐polystyrene (nPS)‐decorated graphene oxide (GO) hybrid nanostructures were successfully synthesized using stepwise microemulsion polymerization, and characterized using Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), field‐emission scanning electron microscopy and transmission electron microscopy. XRD and FTIR spectra revealed the existence of a strong interaction between nPS and GO, which implied that the polymer chains were successfully grafted onto the surface of the GO. The nPS‐decorated GO hybrid nanostructures were compounded with epoxy using a hand lay‐up technique, and the effect of the nPS‐decorated GO on the mechanical, thermal and surface morphological properties of the epoxy matrix was investigated using a universal tensile machine, Izod impact tester, thermogravimetric analysis and contact angle measurements with a goniometer. It was observed that in the epoxy matrix, GO improved the compatibility. © 2017 Society of Chemical Industry     

Shear Plugging and Frictional Behaviour of Composites and Fabrics Under Quasi‐static Loading

Experimental studies are presented on the shear plugging and frictional behaviour of composites and fabrics under quasi‐static loading. The primary focus is on the effect of specimen thickness on quasi‐static shear plugging behaviour. In the present study, quasi‐static shear plugging and through‐the‐thickness frictional tests are carried out on three types of materials. The materials investigated are 2D plain weave E‐glass/epoxy, 2D plain weave T300 carbon/epoxy and 2D plain weave E‐glass fabric. Typical results on shear plugging strength and frictional behaviour are presented. Effect of specimen thickness on quasi‐static shear plugging behaviour is also investigated.     

Metallurgical Studies of Austenitic Stainless Steel 304 under Warm Deep Drawing

Austenitic stainless steel 304 was deep drawn with different blank diameters under warm conditions using 20 t hydraulic press. A number of deep drawing experiments both at room temperature and at 150 ℃ were conducted to study the metallography. Also, tensile test experiments were conducted on a universal testing machine up to 700 ℃ and the broken specimens were used to study the fractography of the material using scanning electron microscopy in various regions. The microstructure changes were observed at limiting draw ratio （LDR） when the cup is drawn at different temperatures. In austenitic stainless steel, martensite formation takes place that is not only affected by temperature, hut also influenced by the rate at which the material is deformed. In austenitic stainless steel 304, dynamic strain regime appears above 300 ℃ and it decreases the formability of material due to brittle fracture as studied in its fractography. From the metallographic studies, the maximum LDR of the material is observed at 150 ℃ before dynamic strain regime. It is also observed that at 150 ℃, grains are coarse in the drawn cups at LDR.